from math import sqrt

def quad(a,b,c):
	'''Returns the solutions of an equation
	of the form a*x**2 + b*x + c = 0'''
	x1 = (-b + sqrt(b**2 - 4*a*c))/(2*a)
	x2 = (-b - sqrt(b**2 - 4*a*c))/(2*a)

	return x1,x2

print(quad(2,7,-15))